1. Field of the Invention
The field of this invention is the telomerase reverse transcriptase gene, specifically the regulation of the expression thereof.
2. Background of the Invention
Telomeres, which define the ends of chromosomes, consist of short, tandemly repeated DNA sequences loosely conserved in eukaryotes. Human telomeres consist of many kilobases of (TTAGGG)n together with various associated proteins. Small amounts of these terminal sequences or telomeric DNA are lost from the tips of the chromosomes during S phase because of incomplete DNA replication. Many human cells progressively lose terminal sequence with cell division, a loss that correlates with the apparent absence of telomerase in these cells. The resulting telomeric shortening has been demonstrated to limit cellular lifespan.
Telomerase is a ribonucleoprotein that synthesizes telomeric DNA. Human telomerase is made up of two components: (1) an essential structural RNA (TER) (where the human component is referred to in the art as hTER); and (2) a catalytic protein (telomerase reverse transcriptase or TERT) (where the human component is referred to in the art as hTERT). Telomerase works by recognizing the 3xe2x80x2 end of DNA, e.g., telomeres, and adding multiple telomeric repeats to its 3xe2x80x2 end with the catalytic protein component, e.g., hTERT, which has polymerase activity, and hTER which serves as the template for nucleotide incorporation. Of these two components of the telomerase enzyme, both the catalytic protein component and the RNA template component are activity limiting components.
Because of its role in cellular senescence and immortalization, there is much interest in the development of protocols and compositions for regulating expression of telomerase.
Relevant Literature
U.S. Patents of interest include: 6,093,809; 6,054,575; 6,007,989; 5,958,680; 5,858,777. Also of interest are WO 99/33998 and WO 99/35243. Articles of interest include: Cong et al., Hum. Mol. Genet. (1999) 8:137-142;
Crowe et al., Nucleic Acids Res. (Jul. 1, 2001) 29:2789-2794; Crowe et al., Biochim Biophys Acta (March 19, 2001) 1518:1-6; Henderson et al., Head Neck (July 2000) 22:347-354; Kim et al., Oncogene (May 10, 2001) 20:2671-82; Takakura et al., Cancer Res. (1999) 59:551-7; and Yasui et al., J.
Gastroenterol. (2000) 35 Suppl. 12: 111-115. See also GENBANK accession nos. AF1 14847 and 128893.
Methods and compositions are provided for modulating, and generally upregulating, the expression of telomerase reverse transcriptase (TERT) by blocking repression of TERT transcription, e.g., by inhibiting binding of repressor factor to a Site C repressor binding site located in the TERT minimal promoter, where in certain embodiments the repressor factor acts in concert with one or more cofactors in binding to the Site C repressor site to inhibit the TERT transcription site. The subject methods and compositions find use in a variety of different applications, including the immortalization of cells, the production of reagents for use in life science research, therapeutic applications; therapeutic agent screening applications; and the like.